From c86deb92db87231d53e549fc91ad97aef7592c5f Mon Sep 17 00:00:00 2001
From: Pavel Mikus <pavel.mikus.mail@seznam.cz>
Date: Thu, 6 Oct 2022 12:19:33 +0200
Subject: [PATCH] improve function name to reflect that it does unscaling
 (to_unscaled_linesf)

---
 src/libslic3r/ExPolygon.hpp        | 13 +++++++++----
 src/libslic3r/GCode/SeamPlacer.cpp |  5 +++--
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/libslic3r/ExPolygon.hpp b/src/libslic3r/ExPolygon.hpp
index 7f2aac628..def2be85a 100644
--- a/src/libslic3r/ExPolygon.hpp
+++ b/src/libslic3r/ExPolygon.hpp
@@ -125,7 +125,7 @@ inline Lines to_lines(const ExPolygons &src)
     return lines;
 }
 
-inline std::vector<Linef> to_linesf(const ExPolygons &src) 
+inline std::vector<Linef> to_unscaled_linesf(const ExPolygons &src) 
 {
     size_t n_lines = 0;
     for (ExPolygons::const_iterator it_expoly = src.begin(); it_expoly != src.end(); ++ it_expoly) {
@@ -138,9 +138,14 @@ inline std::vector<Linef> to_linesf(const ExPolygons &src)
     for (ExPolygons::const_iterator it_expoly = src.begin(); it_expoly != src.end(); ++ it_expoly) {
         for (size_t i = 0; i <= it_expoly->holes.size(); ++ i) {
             const Points &points = ((i == 0) ? it_expoly->contour : it_expoly->holes[i - 1]).points;
-            for (Points::const_iterator it = points.begin(); it != points.end()-1; ++it)
-                lines.push_back(Linef(unscaled(*it), unscaled(*(it + 1))));
-            lines.push_back(Linef(unscaled(points.back()), unscaled(points.front())));
+            Vec2d unscaled_a = unscaled(points.front());
+            Vec2d unscaled_b = unscaled_a;
+            for (Points::const_iterator it = points.begin()+1; it != points.end(); ++it){
+                unscaled_b = unscaled(*(it));
+                lines.push_back(Linef(unscaled_a, unscaled_b));
+                unscaled_a = unscaled_b;
+            }
+            lines.push_back(Linef(unscaled_a, unscaled(points.front())));
         }
     }
     return lines;
diff --git a/src/libslic3r/GCode/SeamPlacer.cpp b/src/libslic3r/GCode/SeamPlacer.cpp
index e18984a64..1d7fd5b3c 100644
--- a/src/libslic3r/GCode/SeamPlacer.cpp
+++ b/src/libslic3r/GCode/SeamPlacer.cpp
@@ -1054,7 +1054,7 @@ void SeamPlacer::calculate_overhangs_and_layer_embedding(const PrintObject *po)
             [po, &layers](tbb::blocked_range<size_t> r) {
                 std::unique_ptr<PerimeterDistancer> prev_layer_distancer;
                 if (r.begin() > 0) { // previous layer exists
-                    prev_layer_distancer = std::make_unique<PerimeterDistancer>(to_linesf(po->layers()[r.begin() - 1]->lslices));
+                    prev_layer_distancer = std::make_unique<PerimeterDistancer>(to_unscaled_linesf(po->layers()[r.begin() - 1]->lslices));
                 }
 
                 for (size_t layer_idx = r.begin(); layer_idx < r.end(); ++layer_idx) {
@@ -1065,7 +1065,8 @@ void SeamPlacer::calculate_overhangs_and_layer_embedding(const PrintObject *po)
                         }
                     };
                     bool should_compute_layer_embedding = regions_with_perimeter > 1;
-                    std::unique_ptr<PerimeterDistancer> current_layer_distancer = std::make_unique<PerimeterDistancer>(to_linesf(po->layers()[layer_idx]->lslices));
+                    std::unique_ptr<PerimeterDistancer> current_layer_distancer        = std::make_unique<PerimeterDistancer>(
+                        to_unscaled_linesf(po->layers()[layer_idx]->lslices));
 
                     for (SeamCandidate &perimeter_point : layers[layer_idx].points) {
                         Vec2f point = Vec2f { perimeter_point.position.head<2>() };